Generally the 4-6 of the Open Natural is just considered the 4-6 of the Open Natural. It has a completetly different character than any of the movements labeled "Continuity" or "Feather", most notably that the final step is not taken O.P.

I guess you'd have to say that the movement is technically Continuity (not closing on 3), and it is an ending (to the Natural Turn). So I guess you *could* call it a Continuity ending. But this would probably be misleading, since most people think of Continuity/Feather endings as specific types of figures, taken RLR (man) and LRL (lady).